liquidio: deprecate 1-bit flag indicating watchdog kernel thread is running

Deprecate the 1-bit flag (bit 2 in the SLI_SCRATCH_1 Octeon register) that
indicates that the liquidio watchdog kernel thread is running for this NIC.
Reason is:  it is incompatible with the firmware's use for SLI_SCRATCH_1.

In lieu of checking that now-deprecated flag, check the value of
oct_dev->adapter_refcount to determine whether or not to create the
watchdog kernel thread.

Signed-off-by: Felix Manlunas <felix.manlunas@cavium.com>
Signed-off-by: Raghu Vatsavayi <raghu.vatsavayi@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>